Exposure Apparatus

ABSTRACT

An exposure apparatus includes an alignment station where an alignment measurement process is executed, an exposure station where an exposure process is executed, and two stages which can be swapped between the alignment station and the exposure station. A first blowing unit blows temperature-adjusted gas toward the alignment station, and a second blowing unit blows temperature-adjusted gas toward the exposure station. The directions in which the first blowing unit and the second blowing unit blow the gases are substantially perpendicular to a direction along which the alignment station and the exposure station are arranged.

This application is a continuation application of copending U.S. patentapplication Ser. No. 11/692,471, filed Aug. 30, 2006.

This application also claims the benefit of Japanese Patent ApplicationNo. 2005-249942, filed on Aug. 30, 2005, which is hereby incorporated byreference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an exposure apparatus and, moreparticularly, to an exposure apparatus comprising two stages, which canbe swapped between an alignment station and an exposure station.

2. Description of the Related Art

In recent years, to improve the processing capability of an exposureapparatus, such as a semiconductor exposure apparatus, a high-speedpositioning apparatus, such as an original stage device or a substratestage device has been under development. In this positioning apparatus,the amount of heat generated by an actuator which drives a stageincreases. The temperature of the optical path of a laser interferometerto align the stage fluctuates due to this heat generation. Thedimensions of members involved vary due to the heat generation as well.These phenomena degrade the position measurement accuracy, as well asthe positioning accuracy.

Japanese Patent Application Laid-Open No. 2000-505958 discloses anexposure apparatus comprising two stages, which can be swapped betweenan exposure station and an alignment station. The exposure apparatusdescribed in Japanese Patent Application Laid-Open No. 2000-505958 canexecute an exposure process in the exposure station and an alignmentmeasurement process in the alignment station in parallel.

In an exposure apparatus which executes an exposure process in anexposure station and an alignment measurement process in an alignmentstation in parallel, when temperature adjusting gas is supplied from theexposure station to the alignment station, the alignment accuracy maydegrade. The same applies to a case wherein the direction in which thetemperature adjusting gas is supplied is reversed.

For example, assume that temperature-adjusted gas adjusts thetemperature of a stage positioned in a measurement processing area in analignment station after adjusting the temperature of a stage positionedin an exposure processing area in an exposure station. In this case, thetemperature-adjusted gas flows into the measurement processing areaafter removing heat in the exposure processing area. This locallygenerates temperature non-uniformity or a temperature gradient in themeasurement processing area. Therefore, the alignment measurementaccuracy degrades in response to a variation in a dimension of a wafer,a wafer chuck, or a stage in the measurement processing area, or avariation in temperature of the optical path for position measurement.As a result, the alignment accuracy degrades. If the dimension or shapeof the wafer in alignment is different from that in exposure, thealignment accuracy degrades as well.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the aboveproblems, and has as its object, e.g., to execute an alignmentmeasurement process and exposure process in exactlytemperature-controlled environments in an exposure apparatus comprisingtwo stages, which can be swapped between an alignment station and anexposure station.

According to a first aspect of the present invention, there is providedan exposure apparatus, which includes an alignment station, in which analignment measurement process is executed, an exposure station where anexposure process is executed, and two stages, which can be swappedbetween the alignment station and the exposure station, comprising afirst blowing unit which blows temperature-adjusted gas toward thealignment station, and a second blowing unit which blowstemperature-adjusted gas toward the exposure station, wherein directionsin which the first blowing unit and the second blowing unit blow thegases are substantially perpendicular to a direction along which thealignment station and the exposure station are arranged.

According to a preferred embodiment of the present invention, theexposure apparatus further comprises a first temperature sensor, whichmeasures the temperature of the gas blown from the first blowing unit, asecond temperature sensor which measures the temperature of the gasblown from the second blowing unit, a first temperature adjusting unitwhich supplies, to the first blowing unit, the gas that istemperature-adjusted in accordance with the temperature measurementresult sent from the first temperature sensor, and a second temperatureadjusting unit which supplies, to the second blowing unit, the gas thatis temperature-adjusted in accordance with the temperature measurementresult sent from the second temperature sensor.

According to a preferred embodiment of the present invention, thedirection in which the first blowing unit and the second blowing unitblow the gases can be a substantially horizontal direction.

Alternatively, according to another embodiment of the present invention,the direction in which the first blowing unit and the second blowingunit blow the gases can be a substantially vertical direction.

According to a preferred embodiment of the present invention, theexposure apparatus may further comprise an air curtain unit, which formsan air curtain between the alignment station and the exposure station.

According to a second aspect of the present invention, there is providedan exposure apparatus which includes an alignment station where analignment measurement process is executed, an exposure station where anexposure process is executed, and two stages which can be swappedbetween the alignment station and the exposure station, the apparatuscomprising a first blowing unit which blows temperature-adjusted gastoward the alignment station, a second blowing unit, which blowstemperature-adjusted gas toward the exposure station, and an air curtainunit, which forms an air curtain between the alignment station and theexposure station.

According to a preferred embodiment of the present invention, the aircurtain unit preferably includes a third blowing unit, which is arrangedbetween the alignment station and the exposure station and blows gas soas to form an air curtain to partition the alignment station and theexposure station.

According to a preferred embodiment of the present invention, the aircurtain unit preferably further includes a third temperature adjustingunit which supplies temperature-adjusted gas to the third blowing unit.

According to a preferred embodiment of the present invention, the aircurtain unit preferably further includes a suction unit which draws gasby suction.

According to a preferred embodiment of the present invention, the thirdblowing unit preferably sprays gas substantially vertically downward toform a downflow.

According to a third aspect of the present invention, there is providedan exposure apparatus, which includes an alignment station, in which analignment process is executed, an exposure station where an exposureprocess is executed, and two stages, which can be swapped between thealignment station and the exposure station, comprising an air curtainunit which forms an air curtain between the alignment station and theexposure station.

According to a fourth aspect of the present invention, there is provideda device manufacturing method comprising steps of causing any one of theabove-described exposure apparatuses to form a latent image pattern on aphotosensitive agent applied to a substrate, and developing the latentimage pattern.

According to the present invention, for example, an alignmentmeasurement process and an exposure process can be executed in exactlytemperature-controlled environments in an exposure apparatus comprisingtwo stages, which can be swapped between an alignment station and anexposure station.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments, with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing an exposure apparatus according tothe first embodiment of the present invention;

FIG. 2 is a schematic view showing an exposure apparatus according tothe second embodiment of the present invention;

FIG. 3 is a schematic view showing an exposure apparatus according tothe third embodiment of the present invention;

FIG. 4 is a flowchart for explaining the device manufacture using anexposure apparatus according to the present invention; and

FIG. 5 is a flowchart showing details of the wafer process in step S4 ofthe flowchart shown in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described belowwith reference to the accompanying drawings.

First Embodiment

FIG. 1 is a plan view showing the schematic structure of an exposureapparatus according to the first embodiment of the present invention. Anexposure apparatus 10, shown in FIG. 1, comprises an exposure station111 and an alignment station 120. The exposure station 111 and alignmentstation 120 share a stage surface plate 112, which provides a referencesurface. The exposure apparatus 10 comprises stages 104 a and 104 bmovable in the X and Y directions on the stage surface plate 112. Theexposure apparatus 10 may comprise a larger number of stages movable inthe X and Y directions on the stage surface plate 112.

An alignment unit, including an alignment optical system, is arranged inthe alignment station 120 and executes a measurement process formeasuring the position of an alignment mark on a wafer. An exposureunit, including a projection optical system, is arranged in the exposurestation 111 and transfers the pattern of an original (reticle) onto aphotosensitive agent applied to the wafer. In this transfer, the waferis aligned in accordance with the result of the measurement processexecuted in the alignment station 120.

The stages 104 a and 104 b can be swapped between the exposure station111 and the alignment station 120. For example, an alignment measurementprocess is executed using the stage 104 a in the alignment station 120in parallel to execution of an exposure process using the stage 104 b inthe exposure station 111. After these processes are completed, thestages 104 a and 104 b can be moved to the exposure station 111 andalignment station 120, respectively. The wafer mounted on the stage 104a, which has moved from the alignment station 120 to the exposurestation 111, has already undergone the alignment measurement process inthe alignment station 120. This makes it possible to execute theexposure process on the basis of that measurement process result, whilealigning the wafer.

Fine moving stages 102 a and 102 b are mounted on the stages 104 a and104 b, respectively. Wafer chucks 103 a and 103 b are mounted on thefine moving stages 102 a and 102 b, respectively. In FIG. 1, wafers 100a and 100 b are held by the wafer chucks 103 a and 103 b, respectively.The fine moving stage 102 a comprises an X mirror 113 a and two Ymirrors 114 a. The X mirror 113 a measures the position of the finemoving stage 102 a (wafer) along the X direction. The Y mirrors 114 ameasure the position of the fine moving stage 102 a (wafer) along the Ydirection. Similarly, the fine moving stage 102 b comprises an X mirror113 b and two Y mirrors 114 b. The X mirror 113 b measures the positionof the fine moving stage 102 b (wafer) along the X direction. The Ymirrors 114 b measure the position of the fine moving stage 102 b(wafer) along the Y direction.

An X laser interferometer 141 a and Y laser interferometer 140 a arearranged in the alignment station 120. The X laser interferometer 141 ameasures the position of the fine moving stage 102 a or 102 b along theX direction by using the X mirror 113 a or 113 b. The Y laserinterferometer 140 a measures the position of the fine moving stage 102a or 102 b along the Y direction by using the Y mirror 114 a or 114 b.

Similarly, an X laser interferometer 141 b and Y laser interferometer140 b are arranged in the exposure station 111. The X laserinterferometer 141 b measures the position of the fine moving stage 102a or 102 b along the X direction by using the X mirror 113 a or 113 b.The Y laser interferometer 140 b measures the position of the finemoving stage 102 a or 102 b along the Y direction by using the Y mirror114 a or 114 b.

Temperature sensors 151 a and 151 b are arranged in the alignmentstation 120 and exposure station 111, respectively.

The alignment station 120 is provided with a temperature adjusting unit152 a and outlet (blowing port) 150 a. The temperature adjusting unit152 a adjusts the temperature in an area 120 a to execute the alignmentmeasurement process in the alignment station 120. The measurementprocessing area 120 a includes, e.g., an area which covers an area wherethe stage 104 a or 104 b moves for the measurement process.

The exposure station 111 is provided with a temperature adjusting unit152 b and outlet (blowing port) 150 b. The temperature adjusting unit152 b adjusts the temperature in an area 111 a to execute the exposureprocess in the exposure station 111. The exposure processing area 111 aincludes, e.g., an area which covers an area where the stage 104 a or104 b moves for the exposure process.

Each of the temperature adjusting units 152 a and 152 b may include,e.g., a cooler and a heater arranged downstream of the cooler. Thecooler may be shared by the temperature adjusting units 152 a and 152 b.If the alignment station 120 and exposure station 111 align themselvesin the Y direction, each of the outlets 150 a and 150 b is preferablyarranged so as to blow temperature-adjusted gas in a direction almostparallel to the X direction perpendicular to the Y direction.

The temperature sensor 151 a is arranged so as to measure thetemperature in the measurement processing area 120 a. The temperaturesensor 151 b is arranged so as to measure the temperature in theexposure processing area 111 a. The temperature measurement resultsobtained by the temperature sensors 151 a and 151 b are sent to atemperature adjustment controller 153. On the basis of the temperaturemeasurement result sent from the temperature sensor 151 a, thetemperature adjustment controller 153 controls the temperature adjustingunit 152 a so as to maintain the measurement processing area 120 a at atarget temperature. Also, on the basis of the temperature measurementresult sent from the temperature sensor 151 b, the temperatureadjustment controller 153 controls the temperature adjusting unit 152 bso as to maintain the exposure processing area 111 a at the targettemperature.

With the above arrangement, the temperatures in the measurementprocessing area 120 a and exposure processing area 111 a can beindependently adjusted. This makes it possible, e.g., to prevent heatgenerated by one of the measurement processing area 120 a and exposureprocessing area 111 a from influencing the other one. Also, with thisarrangement, the alignment measurement process and the exposure processfollowed by alignment according to the obtained measurement processresult can be executed under the same temperature. This makes itpossible to prevent variations in dimensions of a wafer, wafer chuck,and stage, and a degradation in alignment accuracy due, e.g., to avariation in temperature of the optical path of a laser interferometer,thus executing the exposure process with high alignment accuracy.

Also, with this arrangement, the direction of the gas blown from theoutlet 150 a and the direction of the gas blown from the outlet 150 bare parallel to each other. This makes it difficult to allow twotemperature adjusting systems to interfere with the temperatureadjustment of each respective system. Assume here that two temperatureadjusting systems interfere with the temperature adjustment of eachrespective system, and, for example, the temperature adjustingperformance of one of these temperature adjusting systems is improved.At this time, that operation may act on the other temperature adjustingsystem as a disturbance.

In the above-described arrangement, when a temperature (actualtemperature) measured by the temperature sensor 151 a deviates from atarget temperature due to a disturbance during the alignment process,the alignment measurement result may be corrected on the basis of thedifference between the measured temperature and the target temperature.

The temperature sensors 151 a and 151 b are preferably arranged in themeasurement processing area 120 a and exposure processing area 111 a,respectively. However, for example, the temperature sensors 151 a and151 b may be arranged near the outlets 150 a and 150 b, respectively. Inthis case, the temperatures in the measurement processing area 120 a andexposure processing area 111 a cannot be directly measured. However,supplying temperature-adjusted gases into the measurement processingarea 111 a makes it possible to replace the temperature-varied gasesnaturally produced in these areas with temperature-adjusted gases.

Second Embodiment

This embodiment is different from the first embodiment in the directionin which the temperature adjusting gas is blown. The differences fromthe first embodiment will be mainly described here. Details which arenot particularly referred to here can follow the first embodiment.

FIG. 2 is a side view showing the schematic structure of an exposureapparatus according to the second embodiment of the present invention.An exposure apparatus 20, shown in FIG. 2, comprises an exposure station111 and an alignment station 120. The exposure station 111 and alignmentstation 120 share a stage surface plate 112, which provides a referencesurface. The exposure apparatus 20 comprises stages 104 a and 104 bmovable in the X and Y directions on the stage surface plate 112. Analignment unit, including an alignment optical system 101, is arrangedin the alignment station 120 and executes an alignment measurementprocess for measuring the position of an alignment mark on a wafer. Anexposure unit, including a projection optical system 105, is arranged inthe exposure station 111 and transfers the pattern of an original(reticle) onto a photosensitive agent applied to the wafer. In thistransfer, the wafer is aligned in accordance with the result of themeasurement process executed in the alignment station 120.

The alignment station 120 is provided with a temperature adjusting unit152 a′ and outlet 150 a′. The temperature adjusting unit 152 a′ adjuststhe temperature in an area 120 a to execute the alignment measurementprocess in the alignment station 120.

The exposure station 111 is provided with a temperature adjusting unit152 b′ and outlet 150 b′. The temperature adjusting unit 152 b′ adjuststhe temperature in an area 111 a to execute the exposure process in theexposure station 111.

Each of the temperature adjusting units 152 a′ and 152 b′ includes,e.g., a cooler and a heater arranged downstream of the cooler. Thecooler may be shared by the temperature adjusting units 152 a′ and 152b′. If the alignment station 120 and exposure station 111 alignthemselves in the Y direction, each of the outlets 150 a′ and 150 b′ ispreferably arranged so as to blow temperature-adjusted gas in adirection almost parallel to the Z direction (downflow direction)perpendicular to the Y direction.

A temperature sensor 151 a is arranged so as to measure the temperaturein the measurement processing area 120 a. A temperature sensor 151 b isarranged so as to measure the temperature in the exposure processingarea 111 a. The temperature measurement results obtained by thetemperature sensors 151 a and 151 b are sent to a temperature adjustmentcontroller 153. On the basis of the temperature measurement result sentfrom the temperature sensor 151 a, the temperature adjustment controller153 controls the temperature adjusting unit 152 a′ so as to maintain themeasurement processing area 120 a at a target temperature. Also, on thebasis of the temperature measurement result sent from the temperaturesensor 151 b, the temperature adjustment controller 153 controls thetemperature adjusting unit 152 b′ so as to maintain the exposureprocessing area 111 a at the target temperature.

The exposure apparatus 20 according to this embodiment not only bringsabout an advantage similar to that of the exposure apparatus 10,according to the first embodiment, but also, contributes to a reductionin the footprint by arranging the temperature adjusting device andoutlet above the stage base.

Third Embodiment

This embodiment is different from the first and second embodiments inthat a unit which forms an air curtain to partition the environments ofan alignment station and exposure station is provided. The differencesfrom the first and second embodiments will be mainly described here.Details, which are not particularly referred to here, can follow thefirst and second embodiments.

FIG. 3 is a side view showing the schematic structure of an exposureapparatus according to the third embodiment of the present invention. Anexposure apparatus 30, shown in FIG. 3, comprises an exposure station111 and an alignment station 120. The exposure station 111 and alignmentstation 120 share a stage surface plate 112, which provides a referenceplane. The exposure apparatus 30 comprises stages 104 a and 104 bmovable in the X and Y directions on the stage surface plate 112. Analignment unit, including an alignment optical system 101, is arrangedin the alignment station 120 and executes an alignment measurementprocess for measuring the position of an alignment mark on a wafer. Anexposure unit, including a projection optical system 105, is arranged inthe exposure station 111 and transfers the pattern of an original(reticle) onto a photosensitive agent applied to the wafer. In thistransfer, the wafer is aligned in accordance with the result of themeasurement process executed in the alignment station 120.

The alignment station 120 is provided with a temperature adjusting unit152 a″ and outlet 150 a″. The temperature adjusting unit 152 a″ adjuststhe temperature in an area 120 a to execute the alignment measurementprocess in the alignment station 120.

The exposure station 111 is provided with a temperature adjusting unit152 b″ and outlet 150 b″. The temperature adjusting unit 152 b″ adjuststhe temperature in an area 111 a to execute the exposure process in theexposure station 111.

Each of the temperature adjusting units 152 a″ and 152 b″ includes,e.g., a cooler and a heater arranged downstream of the cooler. Thecooler may be shared by the temperature adjusting units 152 a″ and 152b″. The direction of gases blown from outlets 150 a″ and 150 b″ are notparticularly limited. In the example shown in FIG. 3, the outlets 150 a″and 150 b″ are arranged so as to blow gases in the directions in whichthey face each other. The outlets 150 a″ and 150 b″ may blow gases inthe direction shown in the first or second embodiment, or in anotherdirection.

The exposure apparatus 30 according to this embodiment comprises an aircurtain unit, which forms an air curtain to partition the environmentsof the alignment station 120 and exposure station 111. The air curtainunit includes an outlet (blowing port) 150 c, which forms an air curtainbetween the alignment station 120 and the exposure station 111 byutilizing the gas flow in the vertical direction (Z direction). At thistime, the vertical direction can be either downward (in this case, adownflow is formed) or upward. However, the vertically downwarddirection is preferable.

The air curtain unit preferably includes a temperature adjusting unit152 c and causes it to supply temperature-adjusted gas to the outlet 150c. The temperature adjusting unit 152 c can preferably be controlled bya temperature adjusting controller 153 to supply, to the outlet 150 c,gas, whose temperature is adjusted to be equal to a target temperaturein the exposure processing area 111 a and measurement processing area120 a. At this time, the temperature adjustment controller 153preferably controls the temperature adjusting unit 152 c on the basis ofthe temperature measurement result sent from a temperature sensor 151 c,which measures the temperature of gas blown from the outlet 150 c.

The air curtain unit preferably further includes a suction port 154 todraw gas by suction. This makes it possible to prevent gases blown fromthe outlets 150 a″, 150 b″, and 150 c from forming turbulence. When adownflow is to be formed using the air curtain unit, the suction port154 may be prepared for, e.g., the stage base 112.

As described above, forming an air curtain to partition the environmentsof the alignment station 120 and exposure station 111 makes it possibleto independently control the temperatures of the alignment station 120and exposure station 111. It is also possible to increase the degrees offreedom of the direction in which gases are supplied, so as to adjustthe temperatures in the measurement processing area 120 a and exposureprocessing area 111 a.

Application Example

An embodiment of a device manufacturing method using the above-describedexposure apparatus will be described next with reference to FIGS. 4 and5. FIG. 4 is a flowchart for explaining the manufacture of a device(e.g., a semiconductor chip, such as an IC or LSI, an LCD, or a CCD). Asemiconductor chip manufacturing method will be exemplified here.

In Step S1 (circuit design), the circuit of a semiconductor device isdesigned. In step S2 (mask fabrication), a mask is fabricated on thebasis of the designed circuit pattern. In step S3 (wafer manufacture), awafer is manufactured using a material such as silicon. In step S4(wafer process), called a pre-process, the above-described exposureapparatus is caused to form an actual circuit on the wafer bylithography using the mask and wafer. In step S5 (assembly), called apost-process, a semiconductor chip is formed using the wafermanufactured in step S4. This step includes an assembly step (dicing andbonding) and a packaging step (chip encapsulation). In step S6(inspection), the semiconductor device manufactured in step S5 undergoesinspections, such as an operation confirmation test and a durabilitytest. After these steps, the semiconductor device is completed andshipped (step S7).

FIG. 5 is a flowchart showing details of the wafer process in step S4.In step S11 (oxidation), the wafer surface is oxidized. In step S12(CVD), an insulating film is formed on the wafer surface. In step S13(electrode formation), an electrode is formed on the wafer by vapordeposition. In step S14 (ion implantation), ions are implanted in thewafer. In step S15 (resist process), a photosensitive agent is appliedto the wafer. In step S16 (exposure), the exposure apparatus is causedto transfer the mask circuit pattern onto the photosensitive agent onthe wafer to form a latent image pattern on the photosensitive agent. Instep S17 (development), the latent image pattern formed on thephotosensitive agent on the wafer is developed to form a patternedresist mask. In step S18 (etching), portions other than the developedresist image are etched. In step S19 (resist removal), any unnecessaryresist remaining after etching is removed. These steps are repeated toform multiple circuit patterns on the wafer.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

1-14. (canceled)
 15. An exposure apparatus which includes an alignmentstation where an alignment measurement process is executed, an exposurestation where an exposure process is executed, and two stages which canbe swapped between said alignment station and said exposure station, theapparatus comprising: a first blowing unit which blowstemperature-adjusted gas toward the alignment station; and a secondblowing unit which blows temperature-adjusted gas toward the exposurestation, wherein directions in which said first blowing unit and saidsecond blowing unit blow the gases are substantially perpendicular to adirection along which the alignment station and the exposure station arearranged.
 16. The apparatus according to claim 15, further comprising: afirst temperature sensor which measures a temperature of the gas blownfrom said first blowing unit; a second temperature sensor which measuresa temperature of the gas blown from said second blowing unit; a firsttemperature adjusting unit which supplies, to said first blowing unit,the gas that is temperature-adjusted in accordance with a temperaturemeasurement result sent from said first temperature sensor; and a secondtemperature adjusting unit which supplies, to said second blowing unit,the gas that is temperature-adjusted in accordance with a temperaturemeasurement result sent from said second temperature sensor.
 17. Theapparatus according to claim 15, wherein the directions in which saidfirst blowing unit and said second blowing unit blow the gases are asubstantially horizontal direction.
 18. The apparatus according to claim15, wherein the directions in which said first blowing unit and saidsecond blowing unit blow the gases are a substantially verticaldirection.
 19. The apparatus according to claim 15, further comprisingan air curtain unit which forms an air curtain between said alignmentstation and said exposure station.
 20. A device manufacturing methodcomprising steps of: (a) causing an exposure apparatus defined in claim15 to form a latent image pattern on a photosensitive agent applied to asubstrate; and (b) developing the latent image pattern, wherein theexposure apparatus includes: (i) an alignment station where an alignmentmeasurement process is executed; (ii) an exposure station where anexposure process is executed; (iii) two stages which can be swappedbetween the alignment station and the exposure station; (iv) a firstblowing unit which blows temperature-adjusted gas toward the alignmentstation; and (v) a second blowing unit which blows temperature-adjustedgas toward the exposure station, wherein directions in which the firstblowing unit and the second blowing unit blow the gases aresubstantially perpendicular to a direction along which the alignmentstation and the exposure station are arranged.
 21. An exposure apparatuswhich includes an alignment station where an alignment measurementprocess is executed, an exposure station where an exposure process isexecuted, and two stages which can be swapped between said alignmentstation and said exposure station, the apparatus comprising: a firstblowing unit which blows temperature-adjusted gas toward the alignmentstation; a second blowing unit which blows temperature-adjusted gastoward the exposure station; and an air curtain unit which forms an aircurtain between the alignment station and the exposure station.
 22. Anapparatus according to claim 21, wherein said air curtain unit includesa third blowing unit which is arranged between said alignment stationand said exposure station and blows gas so as to form an air curtain topartition said alignment station and said exposure station.
 23. Theapparatus according to claim 22, wherein said air curtain unit furtherincludes a third temperature adjusting unit which suppliestemperature-adjusted gas to said third blowing unit.
 24. The apparatusaccording to claim 22, wherein said air curtain unit further includes asuction unit which draws gas by suction.
 25. The apparatus according toclaim 22, wherein the said third blowing unit ejects gas substantiallyvertically downward to form a downflow.
 26. A device manufacturingmethod comprising steps of: (a) causing an exposure apparatus defined inclaim 21 to form a latent image pattern on a photosensitive agentapplied to a substrate; and (b) developing the latent image pattern,wherein the exposure apparatus includes: (i) an alignment station wherean alignment measurement process is executed; (ii) an exposure stationwhere an exposure process is executed; (iii) two stages which can beswapped between the alignment station and the exposure station; (iv) afirst blowing unit which blows temperature-adjusted gas toward thealignment station; (v) a second blowing unit which blowstemperature-adjusted gas toward the exposure station; and (vi) an aircurtain unit which forms an air curtain between the alignment stationand the exposure station.
 27. An exposure apparatus which includes analignment station where an alignment measurement process is executed, anexposure station where an exposure process is executed, and two stageswhich can be swapped between said alignment station and said exposurestation, the apparatus comprising: an air curtain unit which forms anair curtain between said alignment station and said exposure station.28. A device manufacturing method comprising steps of: (a) causing anexposure apparatus defined in claim 27 to form a latent image pattern ona photosensitive agent applied to a substrate; and (b) developing thelatent image pattern, wherein the exposure apparatus which includes: (i)an alignment station where an alignment measurement process is executed;(ii) an exposure station where an exposure process is executed; and(iii) two stages which can be swapped between the alignment station andthe exposure station; and (iv) an air curtain which forms an air curtainbetween the alignment station and the exposure station.